Temperature sensitive powder?
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Steve Shelp
Well-Known Member
Boss Hoss,
Oh I do check my initial velocity spread. But to me the proof is on paper and not on the chrono. If a load shoots bad across the chrono it will normally be bad on paper at 1000yds. But I've seen loads that were great on the chrono but were not good on paper at 1000 also. My 338 Yogi with VVN170 was a perfect example. GREAT numbers across the chrono(best numbers of any powder I ever tried) but I never shot a single digit group with it in competition.
But the point I was trying to make is that normally if a load at 65F shoots great and has a good ES at 20 or below and then it goes to 90F and the ES goes to 60 then that probably won't be the powder I would use for a load in competition. If it's going to go south that quick I don't want it.
Just this year at the IBS 1000yd Nationals at Quantico in hot weather/and high humidity my last HG target was a 6". My other 2 targets aren't worth mentioning because it was the first time I had fired this rifles all year (since the Natls in NC in 2006) and was tuning the load as I shot. My barrel was setback a thread and rethroated this spring. So it was essentially a new barrel.
Anyway I was able to shoot a 6" group on the last target in not very good conditions. That same 6" 1000yd load, cases, bullets, everything was used in South Dakota the next weekend for the IBS 600yd Nationals in cooler weather, less humid, and whatever the elevation is in Pierre, SD. Finished 3rd in HG overall, 2nd in HG Score, and 5th in HG Group after 8 targets at 600yds. I couldn't tell you what the velocity of my load or the ES is. I have never put this one across the chrono. But I know what it wil do on paper under variying conditions. R22 is a great marriage in my cartridge selection.
Same with my LG. I have used the same 50.5gr load in my 65.x55AI in Colorado, Kansas, Iowa, Ohio, NC, VA, and PA in competition with bullets ranging from 135gr FB up to a custome made 150gr BT on Sierra jackets. I have more than one screamer group out of that rifle. One was in July when you couldn't keep the sweat out of your eyes and another was the last match of the year at NC in late September when it was probably 60-65F and humidity was normal. It has always worked.
No they wouldn't. But I have shot enough 300 Win Mags with R22 and H4831 to know that the 10fps spread they show is a best case scenario for H4831 and the 75fps spread for R22 is probably a worse case scenario. My old standby load in a 300 Win Mag for R22 was normally down in the teens for spread. And I know that load will shoot at long range. Play with loose neck tension, different powder positions, and I can make that number go up or down real easy. It's advertising to me. They don't indicate what their sample size was but any statistican could probably prove it was too small to draw any conclusions from. Speculation on my part though because they didn't indicate it.
Even good loads with throw you bigger numbers once in awhile. And it will drive you crazy. Most of the loads that shooters will say are "single digit" ES numbers...won't repeat it with a larger sample size. You shoot enough across the chrono and that single digit ES will open up to around 20 range if everyone is honest with themselves and includes ALL shots within the calulation. The Oehler M43 sometimes gives me too much data when we are testing out stuff. One of the reason why my chrono gathers more dust these days. Thanks to Dave Tooley telling me to quit wasting my time with it! Thanks Dave. That is personal opinion based on my own realtime data and a suggestion of one of the most consistant long range shooters right now over the last several years. Some live and die by chrono numbers. I use to, but don't anymore.
Steve
J E Custom
Well-Known Member
My experience with reloader 19,22,25 and other powder was based
on actual chronograph results.
I try to load at ambient temperatures to maintain load consistency.
Then when I go to the range and test I allways note the temperature
and the velocity for a history of that load.
What I have found is that there are lots of powder that are temp
sensitive, But the velocity spread was not linear.
20 degrees lower did not reduce velocity as much as 20 degrees
hotter raised it." NOTE " this was muzzle velocity and did not take
into account humidity and wind direction.
I really like the reloader powders but max loads were very bad in
hot weather 100+ temp, I also had the same issues with Imr4350,
4831,4064 and H414 to name a few.
So I have tryed to switch to the extreme powders where possible
and not load the others as hot to avoid the problem.
In a match at camp bullis texas during a 1000 yrd match my zero
increased 4 MOA as the temp went from 78o to over 100o and
I chased the zero over 40" untill it started blowing primers (not
good).
My favorite 7/08 load of H 414 will increase 126 ft/sec from 30o
to 100o.
And with the extreme powders I have not seen this much change,
( 10 to 15 ft/sec ). like the chart that Eaglet supplied shows ,My
data closely agrees . But I still use other brands of powder if I
cant make the extreme powders work.
No matter what powder you use you must know how it performs
at any temp especially at long range to avoid problems.
J E CUSTOM
on actual chronograph results.
I try to load at ambient temperatures to maintain load consistency.
Then when I go to the range and test I allways note the temperature
and the velocity for a history of that load.
What I have found is that there are lots of powder that are temp
sensitive, But the velocity spread was not linear.
20 degrees lower did not reduce velocity as much as 20 degrees
hotter raised it." NOTE " this was muzzle velocity and did not take
into account humidity and wind direction.
I really like the reloader powders but max loads were very bad in
hot weather 100+ temp, I also had the same issues with Imr4350,
4831,4064 and H414 to name a few.
So I have tryed to switch to the extreme powders where possible
and not load the others as hot to avoid the problem.
In a match at camp bullis texas during a 1000 yrd match my zero
increased 4 MOA as the temp went from 78o to over 100o and
I chased the zero over 40" untill it started blowing primers (not
good).
My favorite 7/08 load of H 414 will increase 126 ft/sec from 30o
to 100o.
And with the extreme powders I have not seen this much change,
( 10 to 15 ft/sec ). like the chart that Eaglet supplied shows ,My
data closely agrees . But I still use other brands of powder if I
cant make the extreme powders work.
No matter what powder you use you must know how it performs
at any temp especially at long range to avoid problems.
J E CUSTOM
41mag
Well-Known Member
Most of my loading up until two years ago was using cases based off the '06. In these I found that RL-22 was about the slowest of the the RL powders that I could get to work in the ranges I was looking for. My expereinces with them just about mirrors what J E Custom posted as well.
When Tim and I got into the 270 A.M., the 300 Rum, and 7mm STW one of the changes was nearly double the powder charges we were used to dealing with. Bear in mind we haven't used the 25 in the A.M. but have in the other two. Folks all over the place rave about how well it shot and we had to try it. Well in our experiences with it it shot great in the two rifles, and we were working loads up for them both. However in our area we also found that the changing temps and higher pressures change loads up dramaticaly. Tim had a great load worked up for that RUM and it was shooting around 2" at 500yds. Temps were from the mid 70's to mid 80's. No pressure signs that we noted, velocities were clocked accordingly to what book and other were getting. Then one afternoon with the temps hitting the mid 90's I beared down on some hogs out around 600yds. The first and only shot was amlost like a grenade went off in my face. The case held but it was totally wasted upon removal. Even with the brake the recoil was very noticably different. We checked it again back at the barn and found that the velocity had jumped 200fps, fomr what it had been only a week earlier in lower temps. Two weeks later same load cooler weather back to where it had been.
I saw a similar swing in my STW loads even when working at the higher temps to do development. With mid to upper 80 degree weather for development, I was starting to iron primers as the temps rose up into the mid 90's. With Win cases being hard to come by I dropped the use of 25 for this reason.
I believe that folks who do not have such temp changes or such high temps on a regular basis, or who live in higher elevations, will find loads with this powder that works well especially if they rarely shoot in temps over the mid 80's. However here in the areas we shoot and with temp swings from 40's in the morning to pushing mid to high 80's by mid afternnoon, there are other powders which work better for our purposes. One of them is H-1000, in the bigger cases, and AA8700 had promise but since the supply has dried up to only a trickle it's better to stick with something that will be available for some time. In smaller capacity cases this might not show up as predominantly as it does with the bigger cases, I personally do not have enough experience with them to say. I do however feel that with the several pounds of it we went through in the other calibers that our info is valid from what we experienced. Bottom line is it works well, but it does have issues when the temps change that show up much more so than with other powders of similar burn rates.
C
Chawlston
Guest
The temperature swings that we see in our part of the country are in the neighborhood of 80 degrees. What we found in our testing is that the RL powders are extremely useful and accurate at a specific temperature/humidity relationship. Change one of them 10 degrees or 10%, and the load will not group as before. I burned up a 30/338 Lapua barrel and almost burned up a 338 lapua barrel dealing with the temp/humidity swings. I had to start using moly to try and calm down the pressure spikes. It worked fairly well but it is a pain.....
I zero my guns at 400 yards and when we test them on successive days in different temperature and humidity environments, we noticed that the zeros were significantly more consistent than RL powders.......
Then I got a 338 Lapua improved barrel as well as a 338 RUM barrel and worked them up with retumbo and h1000. I was so impressed with the extreme powders over our temperature and humidity range, that I am in the process (or completed) converting all my chamberings (22/6MM, 6mmbrx, 6mm Dasher, 6x284, 25x284, 6.5x284, 7mm-08 imp, 308 win, 30 STW, 338 Lapua, 338 Lapua imp and 338/378 over to them. I will use the other powders for brass forming and fouling shots.
Here is a test for you to perform...... Pick a rifle and shoot two shots at 400 yards on target. Then on three successive days, go back and shoot one shot on the target and note the temp/humidity. Do this for the extreme powders as well and the non-extreme powders..... If you get similar results that I did, then you will probably want to change over to Extreme powders as well.
I zero my guns at 400 yards and when we test them on successive days in different temperature and humidity environments, we noticed that the zeros were significantly more consistent than RL powders.......
Then I got a 338 Lapua improved barrel as well as a 338 RUM barrel and worked them up with retumbo and h1000. I was so impressed with the extreme powders over our temperature and humidity range, that I am in the process (or completed) converting all my chamberings (22/6MM, 6mmbrx, 6mm Dasher, 6x284, 25x284, 6.5x284, 7mm-08 imp, 308 win, 30 STW, 338 Lapua, 338 Lapua imp and 338/378 over to them. I will use the other powders for brass forming and fouling shots.
Here is a test for you to perform...... Pick a rifle and shoot two shots at 400 yards on target. Then on three successive days, go back and shoot one shot on the target and note the temp/humidity. Do this for the extreme powders as well and the non-extreme powders..... If you get similar results that I did, then you will probably want to change over to Extreme powders as well.
Cleanliness of Extreme Powders
Hi Guys,
Very interesting thread! One thing that I have not seen mentioned is how clean the Hodgdon powders burn. I used to use reloaded 22 and thought it was great. Then I started using Hodgdon H1000 and man what a huge difference in residue. Reloder 22 and even worse, Reloder 25, leave quite a bit of residue behind. It makes me wonder how much the residue build up has to do with extreme spread. As that residue builds up, I certainly notice higher pressures and as a result higher bullet speeds.
Hodgdon powders leave much less residue and don't build up pressure nearly as quickly. You have to wonder how much barrel wear is reduced with clean burning powders as well.
Considering all advantages of the Extreme powders, if you can develop an accurate load with them, the case for switching is self evident.
Regard,
Vic
Hi Guys,
Very interesting thread! One thing that I have not seen mentioned is how clean the Hodgdon powders burn. I used to use reloaded 22 and thought it was great. Then I started using Hodgdon H1000 and man what a huge difference in residue. Reloder 22 and even worse, Reloder 25, leave quite a bit of residue behind. It makes me wonder how much the residue build up has to do with extreme spread. As that residue builds up, I certainly notice higher pressures and as a result higher bullet speeds.
Hodgdon powders leave much less residue and don't build up pressure nearly as quickly. You have to wonder how much barrel wear is reduced with clean burning powders as well.
Considering all advantages of the Extreme powders, if you can develop an accurate load with them, the case for switching is self evident.
Regard,
Vic
JECustom and I have both heard that the Reloader powders are very temperature sensitive. I have a good load in .280 Rem with Reloader 22. Should I be looking for another powder?
found this old thread about tempture sensitive powders and thought this might help fellow members out,this is from hodgdon web site.gun)
CARTRIDGE: 30-06 • CASE: W-W
PRIMER: WLR • BULLET: 165 gr. Hornady SPPOWDERH4350RELODER 19IMR 4350VIT N550AA 4350Pressure 70 Deg. F47,300 CUP47,200 CUP51,400 CUP50,100 CUP47,100 CUPPressure 125 Deg. F47,800 CUP47,800 CUP50,900 CUP60,200 CUP45,100 CUPPressure 0 Deg. F48,000 CUP48,900 CUP51,700 CUP47,600 CUP51,900 CUPVelocity 70 Deg. F2881 f/s2820 f/s2908 f/s2883 f/s2786 f/sVelocity 125 Deg. F2880 f/s2902 f/s2941 f/s2927 f/s2772 f/sVelocity 0 Deg. F2884 f/s2808 f/s2874 f/s2878 f/s2801 f/sPressure Variation (Hot)+500 CUP+600 CUP-500 CUP+10,100 CUP-2,000 CUPPressure Variation (Cold)+700 CUP+1,700 CUP+300 CUP-2,500 CUP+4,800 CUPVelocity Variation (Hot)-1 f/s+82 f/s+33 f/s+44 f/s-14 f/sVelocity Variation (Cold)+3 f/s-12 f/s-34 f/s-5 f/s+15 f/sExtreme Pressure Spread700 CUP1,700 CUP800 CUP12,600 CUP6,800 CUPExtreme Velocity Spread4 f/s94 f/s67 f/s49 f/s29 f/sCARTRIDGE: 300 Win. Mag. • CASE: W-W
PRIMER: WLRM • BULLET: 180 gr. Sierra Boat Tail SPPOWDERH4831SCAA 3100IMR 4831VIT N560RELODER 22Pressure 70 Deg. F54,000 CUP51,800 CUP51,000 CUP52,400 CUP53,000 CUPPressure 125 Deg. F52,800 CUP54,300 CUP54,400 CUP57,000 CUP55,100 CUPPressure 0 Deg. F53,200 CUP51,500 CUP49,400 CUP51,800 CUP52,700 CUPVelocity 70 Deg. F2985 f/s3050 f/s3012 f/s3009 f/s3087 f/sVelocity 125 Deg. F2995 f/s3113 f/s3080 f/s3101 f/s3142 f/sVelocity 0 Deg. F2986 f/s3000 f/s2953 f/s2980 f/s3067 f/sPressure Variation (Hot)-1,200 CUP+2,500 CUP+3,400 CUP+4,600 CUP+2,100 CUPPressure Variation (Cold)-800 CUP-300 CUP-1,600 CUP-600 CUP-300 CUPVelocity Variation (Hot)+10 f/s+63 f/s+68 f/s+92 f/s+55 f/sVelocity Variation (Cold)+1 f/s-50 f/s-59 f/s-29 f/s-20 f/sExtreme Pressure Spread1,200 CUP2,800 CUP5,000 CUP5,200 CUP2,400 CUPExtreme Velocity Spread10 f/s113 f/s127 f/s121 f/s75 f/sCARTRIDGE: 308 Win. • CASE: W-W
PRIMER: WLR • BULLET: 168 gr. Sierra BTHPPOWDERVARGETWIN. 748RELODER 15VIT N140IMR 4064AA 2520Pressure 70 Deg. F51,100 CUP50,200 CUP50,300 CUP49,600 CUP51,100 CUP49,900 CUPPressure 125 Deg. F51,500 CUP51,100 CUP47,300 CUP51,000 CUP49,700 CUP52,600 CUPPressure 0 Deg. F51,200 CUP47,300 CUP48,700 CUP47,500 CUP51,300 CUP50,500 CUPVelocity 70 Deg. F2771 f/s2724 f/s2715 f/s2665 f/s2686 f/s2805 f/sVelocity 125 Deg. F2779 f/s2769 f/s2705 f/s2679 f/s2697 f/s2844 f/sVelocity 0 Deg. F2778 f/s2655 f/s2665 f/s2629 f/s2651 f/s2781 f/sPressure Variation (Hot)+400 CUP+900 CUP-3,000 CUP+1,400 CUP-1,400 CUP+2,700 CUPPressure Variation (Cold)+100 CUP-2,900 CUP-1,600 CUP-2,100 CUP+200 CUP+600 CUPVelocity Variation (Hot)+8 f/s+45 f/s-10 f/s+14 f/s+11 f/s+39 f/sVelocity Variation (Cold)+7 f/s-69 f/s-50 f/s-36 f/s-35 f/s24 f/sExtreme Pressure Spread400 CUP3,800 CUP3,000 CUP3,500 CUP1,600 CUP2,700 CUPExtreme Velocity Spread8 f/s114 f/s50 f/s50 f/s46 f/s63 f/sCARTRIDGE: 22-250 Rem. • CASE: W-W
PRIMER: WLR • BULLET: 55 gr. Speed FMJ-BTPOWDERH4895VIT N140RELODER 12AA 2460IMR 4895Pressure 70 Deg. F49,500 CUP48,700 CUP51,700 CUP50,000 CUP48,100 CUPPressure 125 Deg. F48,700 CUP50,500 CUP49,400 CUP54,100 CUP52,300 CUPPressure 0 Deg. F49,700 CUP46,800 CUP51,900 CUP48,700 CUP48,000 CUPVelocity 70 Deg. F3742 f/s3662 f/s3607 f/s3671 f/s3699 f/sVelocity 125 Deg. F3748 f/s3692 f/s3609 f/s3707 f/s3791 f/sVelocity 0 Deg. F3728 f/s3611 f/s3633 f/s3673 f/s3625 f/sPressure Variation (Hot)-800 CUP+1,800 CUP-1,700 CUP+4,100 CUP+4,200 CUPPressure Variation (Cold)+200 CUP-1,900 CUP+200 CUP-1,300 CUP-100 CUPVelocity Variation (Hot)+6 f/s+30 f/s+2 f/s+36 f/s+92 f/sVelocity Variation (Cold)-14 f/s-51 f/s+26 f/s+2 f/s-74 f/sExtreme Pressure Spread1,000 CUP3,700 CUP1,900 CUP5,400 CUP4,300 CUPExtreme Velocity Spread20 f/s81 f/s26 f/s36 f/s166 f/s
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J E Custom
Well-Known Member
Onager
New Member
No where near the experience you guys have but here is my experience with RL22 and two 300 RUM
My brother and nephew asked me to work up the a load that would work in both Remington 700s using this powder. They also hoped I could find the same load that was interchangable in both guns. Riiiiiight.
Surprisingly, much easier than I thought. One is a standard 700 in a glass bedded laminated stock. The other is a heavy fluted barrel in a expensive pillar bedded synthetic stock. Barrels broken in on both. Each of the guns supposedly hated factory ammo.
I used 180 gr Barnes TTsx bullets. I found that 87 grains of Rl 22 gave the best accuracy. I avoided pushing the load over 87.5 grains because, of the temp. sensitivity fear and they aren't my guns.
Fired all groups at 300 yards.
The one day the temp was in the 80s and I had "cooked" the rounds in my car all day. Can't remember the velocity average at the moment. Groups were 0.5 moa(great for me). No pressure signs but velocity was a bit higher than my goal.
This winter I completed the project. Temperatures were in the 30s to high of 40 degrees F.
Excellent groups again but the one group poi was 3 1/2 inches lower in the cooler weather. No horizontal deviation. The velocities averaged 150 fps less. In my brothers gun the poi was 3 inches lower in the cooler weather. With an average loss in velocity of 125 fps.
They are happy that the 87 grains works in both guns and they got much better accuracy.
My take away is that "pressure sensitive" powders can/do give good accuracy but I will not push the velocity to the upper limits.
My brother and nephew asked me to work up the a load that would work in both Remington 700s using this powder. They also hoped I could find the same load that was interchangable in both guns. Riiiiiight.
Surprisingly, much easier than I thought. One is a standard 700 in a glass bedded laminated stock. The other is a heavy fluted barrel in a expensive pillar bedded synthetic stock. Barrels broken in on both. Each of the guns supposedly hated factory ammo.
I used 180 gr Barnes TTsx bullets. I found that 87 grains of Rl 22 gave the best accuracy. I avoided pushing the load over 87.5 grains because, of the temp. sensitivity fear and they aren't my guns.
Fired all groups at 300 yards.
The one day the temp was in the 80s and I had "cooked" the rounds in my car all day. Can't remember the velocity average at the moment. Groups were 0.5 moa(great for me). No pressure signs but velocity was a bit higher than my goal.
This winter I completed the project. Temperatures were in the 30s to high of 40 degrees F.
Excellent groups again but the one group poi was 3 1/2 inches lower in the cooler weather. No horizontal deviation. The velocities averaged 150 fps less. In my brothers gun the poi was 3 inches lower in the cooler weather. With an average loss in velocity of 125 fps.
They are happy that the 87 grains works in both guns and they got much better accuracy.
My take away is that "pressure sensitive" powders can/do give good accuracy but I will not push the velocity to the upper limits.
rscott5028
Well-Known Member
I agree with JE that you don't necessarily need to change if you already have a good load that meets your needs.
The key to success would be to get dope on your rifle/load under the conditions that best represent what you'll experience when hunting.
I have a small sample of data from my own rifles that seems to corrobrate Hodgdon's claims. And, I plan to stick with h4831sc in my 6.5x284 12F rifle.
But, RL22 is still good enough for much of the hunting that I do.
--richard
The key to success would be to get dope on your rifle/load under the conditions that best represent what you'll experience when hunting.
I have a small sample of data from my own rifles that seems to corrobrate Hodgdon's claims. And, I plan to stick with h4831sc in my 6.5x284 12F rifle.
But, RL22 is still good enough for much of the hunting that I do.
--richard
About a year ago or so on this site, there was a post in a thread listing powder sensitivity in order from most to least. Not sure what tests it was based on, but I can't seem to find it now. Anybody remember where that is? Seems relevant to the discussion at hand.
